Filling and venting plug for storage battery cells



April 29, 194i. H C, puc-G5 ETAL ZQ FILLING AND VENTING PLUG FOR STORAGEBATTERY CELLS Filed Dec. '7, 1938 Patented Apr. 29, @4l

Medial.

FILLING AND VENTENG PLUG FOB- STGBAGE BATTERY CELLS Harold Riggs,Langhorne, and William C. Leingang, llhiladelphias Fa., assgnors to TheElectric Storage @on-inem?, Philadelphia, Pai, a corporation of New.licrsey Application December 7, 193%, Serial No. 244,32@

e claims.

- a storage battery cell.

More specincally, our invention consists in the provision of a storagebattery cell having the customary iilllng and venting conduit orV apexture passing 'through theL cell cover to a point spaced from the underside of the cell cover. There is also an auxiliary vent or conduitpassing through the cell cover and vcommunicating with the interior ofthe cell at a point above the point of communication of the normalconduit or aperture and closely adjacent the under side of thecell-cover. In the normal conduit or aperture, there is a iioatsupported on the free surface of the electrolyte and adapted, when thecustomary vent plug is removed and the level of the electrolyte raisedto the desired level, to close off thev auxiliary conduit or aperture.When the vent plug is replaced in the normal conduit or aperture, itdepresses the iioat and thereby opens the auxiliary conduit or aperture.

In the accompanying drawing, the single figure shows a vertical` sectionof a portion of the cover of a battery cell with the iilling vent andvent plug, the latter being removed from the vent opening.

in the selected embodiment of our device chosen for illustration anddescription, l is the cover of the cell through which passes a ventingand iilling duct 2 surrounded by the boss 3 above the upper surface ofthe cover and a cylindrical tube @l below the under surface of thecover. Auxiliary vents b are shown passing through the tube l near theunder surface of the cover, which vents, when open, permit gas trappedin the space under the cover to escape at suolil times as the level ofthe electrolyte is sumciently high to prevent the escape of this gasthrough the opening 2. A float valve member B is shown having anupwardly extending cylindrical portion 'i loosely fitting within thetube l closed at its upper end except for the aperture 8, which apertureis suflllciently large to permit water to be added to the cell and topermit the insertionof the intake tube of a hydrometer syringe.Extending from the cylindrical member 'l and surrounding the same is alateral disk-like extension 9 provided with a downwardly projectingannular portion l whose lower rim H lies in a plane just below themaximum desired level of the electrolyte as shown at I2. The tube 1extends downwardly below the disk 9 and terminates in the plane o thelower edge Il of the extension Illas shown at I3. As a result of thisconfiguration, there is provided an annular space iii in which gas istrapped to provide sumcient buoyancy to litt the valve member t to itsupper position in which it closes the vente t when the level of theelectrolyte reaches the desired height during the filling operation. .Byclosing these vents Ei gas is trapped in the space l5 under the cover,preventing the electrolyte from rising any further into this space. ifthe filling operation is continued, the level in the duct 2 will rise toa point where the surface can be observed and the lling operation willbe stopped.

The boss 3 is provided with internal screwthreads it adapted to engagewith the external threads il of the vent plug it. This vent'plug has adownwardly projecting, cylindrical extension i3 adapted to engage theupper surface of the tube l and depress the valve member t when the ventplug is inserted in the duct 2, thus opening the vents and permittingthe trapped gas in the space l5 to escape through vents 2li in thecylindrical extension lil and thence through vent 2i .into theatmosphere. The level of the liquid in the opening 2 will then drop tothe normal electrolyte level l2, the latter rising slightly due to theaddition of a small amount of liquid from the vent opening 2.

It will be understood that, because of the liquid held by capillaryattraction in the space between the tube 'i and the inner wall of theduct d, it will be necessary to provide only a loose t between the tubel and the duct l in order to seal orf the vents 5 when the valve membert is in its upper-n most position.

We do not intend to be limited save as the scope of the prior art and ofthe attached claims may require.

We claim:

1. In a storage battery cell having a cover and containing electrolyte,a iilling and venting structure comprising, in combination, a walldefining a filling and venting duct through the cell cover extendingdownwardly below the cover, an auxiliary vent through said wall at apoint lust below the under surface oi' the cover, a iloat valve memberadapted to float on the surface of the electrolyte and having a portionloosely fitting with capillary clearancel thejinner surface of the wallof the duct and adapted to rise and fall with said electrolyte level andhaving an imperiorate portion adapted to close and open said auxiliaryvent, andra vent plug adapted to be inserted in said filling and ventingduct and to engage said float valve to move it to the vent openingposition, said oat valve member being shaped to provide a passage forthe introduction 'of liquid at the electrolyte level when the vent plugis removed.

2. In a storage battery containing liquid electrolyte spaced below itstop, a illing and venting structure comprising, a cell cover for saidbattery having a lling and venting duct passing therethrough andcommunicating with the interior of the battery above the normalelectrolyte level and below the under side of the cover, an auxilaryvent communicating with the interior of the cell just below the underside o the cover and above the point of communication of said duct andcommunicating with said duct above the point of communication of saidduct with the interior of the cell, a oat having sliding engagement withsaid duct and mounted on the free surface of the electrolyte and havingan imperforate portion located above the free surface of the electrolyteand arranged to open and close said auxiliary vent and spaced from thewalls of said duct a suiicient distance to provide for 15 and theelectrolyte is at its normal level.

LD C. RIGGS. 1|' .i 1 C. LEINGANG'.

